I live here in pa. where more and more the emission laws are becoming more and more strict. I was woundering, I'm thinking of a new cat. back exhaust system installed in a local exhaust shop, and was woundering if my truck will pass emission inspection if I remove the second cat. And how much extra sound will it actually give me with 3-inch dual tips? Please post and/or email me with any suggestions will be very help full. Oops! i forgot to include the important stuff, I have a 1988 Ford F-150 custom, I-6, 4-speed (t-18or19 trans), 4X4, 3.55 gears, with 15X8 z-racing 5 spoke rims, with 32X11.50r15 bfgoodrich mud raidals. i think that is enough, thanks again for any help.

 

Here in Houston, Texas, we have a tailpipe sniffer
and visual smog test. Your truck will not pass emissions if you remove that second cat, but your truck will wake up with just the cat-back system installed. I use a Gibson single-exhaust 3-inch system, which hangs off the original hangers and went on in a couple of hours in my driveway. The seat of the pants increase was phenomenal, and if I had it to do over again I'd use the same system in stainless, and give some real close thought to using a dual-out system under the rear bumper; I didn't dual it at the time because I would have had to lose the spare tire.
I have read posts here where guys didn't use the muffler, just ran straight back from the cat. You may want to go back through the archives and read some of those.
The system currently on my truck (originally a 300-6, now a 337-6) is a pair of Clifford "Street Rod" headers w/smog hookups, a "Y"-hookup from the two collectors into a 3-inch Random Technologies high-flow cat originally designed for a C***y Camaro, then into the Gibson system, for a smooth 3-inches all the way. It passes the sniffer with a pretty good margin, and has a really nice rap to it on acceleration. The drone inside is noticable at highway speeds, and this with a muffler. You may want to consider that last before you lose the quieting pieces.
Eddie

 

I had the 300 in my '87 and the I had the truck tested before the original change, it passed with flying colours. The original slowly fell off and I wanted dual tails but didn't get into all the aftermarket companies. I just went to a local muffler shop (Speedy) and had them install a 351 muffler with the dual chrome tip tails. Really nice change over the original, more power and just a shade more rumble. A year later tested the truck again to make sure and all was well till the cat. plugged up. When the dealership got the replacement, there was only one cal. like section. It ends up that the original had a resonator and then the cat behind it but they are very similar in look. The new cat only had one cat. like section (the cat.). Once this was put onto the truck with the new exhaust, it made a big difference in the throttle reaction. Probably the best thing that ever happened to the truck and was a major benefit in the long run. Very happy with all that happened, I now have a '94 Supercab and looking forward to exhaust change on it. Not sure where to start but there is a great number of choices out there. This truck also has the resonator and cat in different sections. Thinking about taking original cat off and replacing with new one (single) but I have heard that here in Canada there could be a major fine for doing such a job. Not sure, will definitly check into that. Definitly change the complete system from headers to tail if you can but watch out for charges if the cat. still works correctly.

Dean

 

If you have the same Cat type things in your stock exhaust as My 84 had, you can remove the "damaged" Cats and replace them with a Single High Flow Cat. Depending on the Exhaust shop I go to, I am either told the 2nd one is a resonator or a CAT. In my case it didn't matter, I have hit my CATS on the Trail so many times that they were flat and plugged (more flat that usual). I have them remove them and replace it with a "new" High Flow Cat and put it above a cross member so I would not break this one (They aren't cheap). This was done in Arizona and I had to go through a Referee (Stat inspector that has the final say after the inspection station and myself has a disagrement) for my Air Injection system. The State Inspector does a more thorough inspection and will actuall crawl around a vehical to see what's going on or what you have. The removal of the CAT is more of a federal offense than a state inspection (but they do inforce it) and the last I heard you can change a damaged CAT with the same or better only.

The best way to find out is to call the State inspector (not local inspection station) and tell them you have Bad CATS (plugged) and you want to replace the 2 piece set with a Single High Flow CAT and see what they say.

Mark
mark@legendz.com
<a href="Http://mark.legendz.com">Http://mark.legendz.com</a>
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Mark: I was aware the "replace only if damaged" Federal-offense thing.
Trust me, sir.
Those aren't sledge-hammer marks, officer. It fell off and got mashed flatter than week-old road kill by accident. I really didn't mean to back over the f***ing thing thirteen times.
Honest.
Fast Eddie